Fluid oscillator



Sept. 19, 1967 g, RO BER 3,342,198

FLUID OSCILLATOR Filed Jan. 15, 1965' I I 14 I 101A POSITION B PRESSURE FLUID SOURCE SCALE FOR CALIBRATION PRESSURE FLUID SOURCE 36 ADJUSTMENT. LEVER INVENTOR. EuaE/v GROEBER BY WM A TTOR/VE) United States Patent 3,342,198 FLUID OSCILLATOR Eugen Groeber, Salt Lake City, Utah, assignor to Sperry Rand Corporation, Great Neck, N.Y., a corporation of Delaware Filed Jan. 15, 1965, Ser. No. 425,746 2 Claims. (Cl. 137-815) The present invention relates to pure fluid devices and particularly to pure fluid logic devices of the type suitable for use in fluid digital computer systems.

The present invention provides a pure fluid oscillator which may also be utilized as a pressure or velocity limit switch.

The present invention is extremely simple and operates reliably over its intended range of operation for long intervals inspite of adverse environmental conditions. In addition, its oscillating frequency may be varied as a function of the pressure or velocity of the fluid stream over a desired range.

It is a primary object of the present invention to provide a fluid oscillator that is reliable, easy to manufacture and maintains its oscillating characteristic consistently over a long period of time and under adverse environmental conditions.

It is a further object of the present invention to provide a fluid logic device which performs an oscillating function up to a predetermined fluid pressure and in excess of said predetermined pressure acts as a pressure limit switch.

The above objects are achieved by utilizing a pure fluid logic element having a power stream input channel and first and second diverging output channels communicating with an interaction chamber. A resilient cantilevered member is supported with its free end extending into the interaction chamber in order that the power stream emanating from the power stream input channel impacts upon the free end of the cantilevered member. The cantilevered member vibrates in accordance with the pressure of the power stream below a predetermined pressure while above the predetermined pressure, the member is stationary and acts as a pressure limit switch. In order to provide variable oscillating characteristics, the cantilevered member may be made adjustable.

These and other objects of the present invention will become apparent by referring to the drawings in which:

FIG. 1 is a schematic diagram of a bistable fluid logic device incorporating the present invention; and

FIG. 2 is a schematic diagram of a pure fluid logic device incorporating an adjustable resilient member in accordance with the present invention.

Referring to FIG. 1, the pure fluid logic device of the present invention has a power stream input channel 11 connected to an interaction chamber 12 by means of an orifice 13 which defines a fluid power stream emanating from the orifice 13 into the interaction chamber 12. The other extremity of the power stream input channel 11 is connected to a pressure fluid source indicated by the legend. First and second diverging output channels 14 and 15 also communicate with the interaction chamber 12 and define first and second output paths of fluid flow respectively. The output channels 14 and 15 diverge from a common wedge 16 disposed therebetween which is preferably truncated and forms one wall of the interaction chamber 12. The other walls of the interaction chamber 12 may be formed by extensions of the exterior walls of the output channels 14 and 15. The pure fluid logic device 10 may be generally of the type shown in United States Patent Number 3,122,165 entitled, Fluid- Operated System, issued Feb. 25, 1964, to B. M. Horton or of the type shown in United States patent application Ser. No. 352,468 entitled, Multi-Mode Fluid Device, of Fox and Goldschmied filed Mar. 17, 1964.

3,342,198 Patented Sept. 19, 1967 A resilient cantilevered member preferably in the form of a thin flat reed 20 has one end. 21 secured to the inside wall of the output channel 14 which forms a portion of the wedge 16. The reed 20 is supported on the wedge 16 in cantilevered fashion with its free end 22 extending within the interaction chamber 12 where it is cooperative with the power stream emanating from the orifice 13. The reed 20 is made of a material having a predetermined resilience and a thermal coeflicient of expansion compatible with the desired application. The free end 22 of the reed 20 is arranged to vibrate as a function of the pressure or velocity of the power stream emanating from the orifice 13. The frequency of the oscillation of the free end 22 is determined by the dimensions of the reed 20, the resilient properties of the reed material, and the velocity of the power stream. Increasing the power stream velocity increases the frequency of the oscillations until it reaches a maximum. Then as the velocity continues to increase, the frequency decreases slightly until finally at a predetermined velocity the free end 22 of the reed 20 stops vibrating and remains in a predetermined position. With the configuration shown in FIG. 1, the reed 20 stops vibrating adjacent position A because the reed 20 is asymmetrically mounted on the wedge 16.

In operation, with pressure fluid supplied to the power stream input channel 11, the power stream emanating from the orifice 13 causes the free end 22 of the reed 20 to start vibrating back and forth between the side walls of the interaction chamber 12, as shown by the dotted lines, i.e., between position A and position B. When the reed 20 touches at position A, the output channel 15 is cut off and the power stream escapes through the output channel 14. Similarly, when the reed 20 touches at position B, the output channel 14 is cut off and the power stream escapes through the output channel 15. Thus, the vibration of the cantilevered reed 20 provides a pulsating fluid flow from both output channels 14 and 15 thereby achieving its oscillatory characteristic.

As the velocity of the power stream jet increases, the frequency of the vibration of the reed 20 increases until it reaches a maximum. Then as the velocity continues to increase, the frequency decreases slightly and finally at a predetermined velocity, the vibration of the reed 20 ceases and the reed 20 stops at a predetermined position, in this instance, position A. This phenomena therefore provides a fluid velocity limit switch because the velocity at which the vibration stops is constant and controllable.

A combination fluid oscillator and pressure limit switch of the type shown in FIG. 1 has been constructed wherein the overall device 10 was long and /1" wide with 0.1" deep air channels. The interaction region was 0.14" long and the cantilevered length of the reed extending into the interaction region 12 was 0.12" long. The width of the reed 20 preferably is a few thousandths of an inch less than the depth of the air channels for free vibration of the reed 20 while providing good control of the fluid flow. The optimum dimensions of a reed 20 for a particular application may be calculated in accordance with the formulas relating to cantilevered springs. To render the reed 20 relatively insensitive to temperature variations, it may be fabricated from materials having a low thermal coefiicient of expansion, such as the materials used for hair springs in watches.

The fluid oscillator and pressure limit switch shown in FIG. 1 has a vibrating reed 20 which is mounted asymmetrically for dividing the fluid flow which results in a flow division which is unequal in volume and speed. Referring to FIG. 2, a variable fluid flow divider 30 may be provided by locating the vibrating reed 31 at the center of the wedge 32 and by supporting the fixed end 33 of the reed 31 in a pivot 34, as shown in FIG. 2. The pivot 34 may be turned or adjusted as desired from the outside of the device 30 from the symmetrical position shown. The position of the free end 35 of the reed 31 may be determined by means of a graduated scale 36 cooperative with the adjustment lever 37 connected to the reed 31. By turning the adjustment lever 37, the free end 35 of the reed 31 is positioned thereby changing the amplitude between the central position of the reed 31 and the side walls 40 and 41 of the output channels 42 and 43, respectively. Thus, a controllable asymmetrical vibration of the reed 31 is provided. The pivot 34 may be held by friction once it is set or by other known means. The operation of the device of FIG. 2 is otherwise similar to that described above with respect to FIG. 1.

While the invention has been described in its preferred embodiments, it is to be understood that the words which have been used are Words of description rather than limitation and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of the invention in its broader aspects.

What is claimed is:

1. A pure fluid logic device comprising (a) a pure fluid logic element having a power stream input channel for defining a power stream, first and second output channels each defining a path of fluid flow and an interaction chamber disposed between and communicating with said channels,

(b) said channels being divergent with respect to a wedge therebetween which defines a portion of said interaction chamber, and

(c) a resilient cantilevered reed supported on said wedge with its free end extending within said interaction chamber and adapted to be cooperative with said power stream for vibrating upon impaction of said power stream on its free end for directing said power stream alternately through one output channel and then the other, wherein said reed is asymmetrically mounted on said Wedge for vibrating in accordance with said power stream below a predetermined power stream velocity, and above said predetermined velocity, said reed remains in a predetermined position thereby acting as an oscillator below said predetermined velocity and as a limit switch above said predetermined velocity.

2. A pure fluid logic device of the character described in claim 1 wherein said reed is adjustably mounted on said wedge for providing variable oscillator characteristics.

References Cited UNITED STATES PATENTS 1,905,733 4/1933 Moore. 2,777,251 1/1957 Bailey 46-179 3,053,176 9/1962 Woodward 13781.5 3,158,166 11/1964 Warren 137-81.5 3,238,958 3/1966 Warren et al. 13781.5

S. SCOTT, Assistant Examiner.

30 M. CARY NELSON, Primary Examiner. 

1. A PURE FLUID LOGIC DEVICE COMPRISING (A) A PURE FLUID LOGIC ELEMENT HAVING A POWER STREAM INPUT CHANNEL FOR DEFINING A POWER STREAM, FIRST AND SECOND OUTPUT CHANNELS EACH DEFINING A PATH OF FLUID FLOW AND AN INTERACTION CHAMBER DISPOSED BETWEEN AND COMMUNICATING WITH SAID CHANNELS, (B) SAID CHANNELS BEING DIVERGENT WITH RESPECT TO A WEDGE THEREBETWEEN WHICH DEFINES A PORTION OF SAID INTERACTION CHAMBER, AND (C) A RESILIENT CANTILIEVERED REED SUPPORTED ON SAID WEDGE WITH ITS FREE END EXTENDING WITHIN SAID INTERACTION CHAMBER AND ADAPTED TO BE COOPERATIVE WITH SAID POWER STREAM FOR VIBRATING UPON IMPACTION OF SAID POWER STREAM ON ITS FREE END FOR DIRECTING SAID POWER STREAM ALTERNATELY THROUGH ONE OUTPUT CHANNEL AND THEN THE OTHER, WHEREIN SAID REED IS ASYMMETRICALLY MOUNTED ON SAID WEDGE FOR VIBRATING IN ACCORDANCE WITH SAID POWER STREAM BELOW A PREDETERMINED POWER STREAM VELOCITY, AND ABOVE SAID PREDETERMINED VELOCITY, SAID REED REMAINS IN A PREDETERMINED POSITION THEREBY ACTING AS AN OSCILLATOR BELOW SAID PREDETERMINED VELOCITY AND AS A LIMIT SWITCH ABOVE SAID PREDETERMINED VELOCITY. 